ISIS is all too familiar with being on the receiving end of a drone strike, but disturbing footage uploaded by an ISIS supporter suggests they’re experimenting with drones too.

Iraqi forces have already reported low-budget “aerial strikes” from little more than toy drones equipped with homemade bombs. The DoD has already started researching countermeasures to the cheap but deadly ISIS drones like the one featured in the video below.

Concern about weaponized hobbyist drones has been around for years, but only recently has an actual threat emerged.

According to reports in the New York Times, Kurdish forces fighting ISIS in Northern Iraq captured a small reconnaissance drone no bigger than a model airplane late in 2016. By October of 2016 American commanders in Iraq issued warnings about small hobbyist drones equipped with explosive devices.

Iraqi forces have captured some of these weaponized drones that have been modified to house a small “bomblet” that can be deployed by the controller. The DoD is reportedly investigating a variety of countermeasures not limited to laser guided anti-air projectiles and broadband jamming technology.

As drones become more and more commonplace in civilian life, it is only a matter of time before they are used by terrorists for extreme acts of violence in highly populated areas.